

seasons = ['Spring', 'Summer', 'Fall', 'Winter']
list(enumerate(seasons))
# [(0, 'Spring'), (1, 'Summer'), (2, 'Fall'), (3, 'Winter')]
list(enumerate(seasons, start=1))       # 下标从 1 开始
# [(1, 'Spring'), (2, 'Summer'), (3, 'Fall'), (4, 'Winter')]
